1. Field of the Invention
The present invention relates to a fuel atomizing-injection apparatus for internal combustion engines and, more particularly, to a fuel atomizing-injection apparatus installed between a fuel injection device and a suction manifold of an engine and used for promoting vaporization of fuel injected from the fuel injection device into the suction manifold, thus finally allowing the injected fuel to be more effectively and actively mixed with atmospheric air used as combustion air into mixed gas.
2. Description of the Prior Art
As well known to those skilled in the art, a fuel injection device is used with an internal combustion engine, and mixes liquid fuel with combustion air at an appropriate ratio to form mixed gas. Such a conventional fuel injection device comprises several systems: a fuel supply system, a combustion air supply system, and a control system. In the fuel injection device, the fuel supply system pumps fuel from a fuel tank using a fuel pump so as to feed the fuel under high pressure to a fuel injector. The fuel supply system also maintains the pressure of the fuel, thus improving the precision of the fuel injecting operation. On the other hand, the combustion air supply system comprises an inlet airflow sensing device, a throttle body, and a surge tank, and is used for controllably feeding combustion air under pressure into a cylinder in accordance with the opening proportion of a throttle valve or of an air valve. The control system senses the quantity of inlet air, an engine rpm, and the opening proportion of the throttle valve prior to outputting sensing signals to a microcomputer. The control system also controls the fuel injection timing and the target quantity of injected fuel in response to input signals from a variety of sensors, such as a coolant temperature sensor and a combustion air temperature sensor.
When the fuel supply system of the conventional fuel injection device pumps fuel from the fuel tank using the fuel pump, the fuel primarily passes through a fuel filter so as to be filtered prior to being appropriately distributed to the fuel injector and a cold start injector by a delivery pipe. In such a case, a pressure regulator controls the pressure of fuel flowing to the fuel injector, and always maintains a desired fuel pressure higher than the inner pressure of the suction manifold. The pressure regulator also returns remaining fuel from the injector into the fuel tank.
The fuel injector injects fuel into the suction manifold in response to a control signal output from the microcomputer. The fuel injector comprises a solenoid coil, a plunger and a needle valve. In an operation of the injection device, the plunger is retracted with the solenoid coil being electrically activated, and so the needle valve integrated with the plunger opens the injection nozzle of the fuel injector, thus allowing the nozzle to inject the pressurized fuel into a cylinder. In such a case, the quantity of injected fuel is determined by the period of time when the needle valve is opened. That is, the quantity of injected fuel is determined by the period of time when the solenoid coil is turned on.
However, the conventional injection device cannot finely atomize the fuel during the injection of fuel, and so it is almost impossible to effectively mix the fuel with the combustion air. This finally reduces the combustion efficiency of the mixed gas in addition to consuming of an excessive quantity of fuel, and exhausts a variety of harmful unburnt gases into the atmosphere, thus causing environmental pollution, such as air pollution.